I. Field of the Invention
This invention relates generally to material handling equipment and, more particularly, to a grasping device attached to a refuse collection vehicle for handling containers during collection efforts.
II. Discussion of the Prior Art
As the world of materials handling becomes more mechanized the desire to move objects with minimal human intervention increases. Raw materials must be moved from one facility to another for mass production; products must be shipped to users; and refuse must be removed. Mechanized devices have been created to move material and reduce the human intervention needed.
Mechanized material handling devices of the class of interest to the present invention usually have a grasping device attached to a large arm or other means for lifting, moving and tipping a container or object of interest. The grasping device often has a pair of spaced and opposed mechanical arms which function to grasp and release a container by closing down and opening up as operated by one or more actuating devices, such as hydraulic cylinders. In situations where only one actuating device is used, a linkage mechanism is required to achieve dual arm movement.
Grasping devices including a single actuator and a pair of arcuate arms are described in U.S. Pat. No. 4,461,608, to Boda; U.S. Pat. No. 4,708,570, to Smith et al; and U.S. Pat. No. 5,026,104, to Pickrell. Each of the devices described in these patents includes a relatively complex linkage mechanism. Boda describes an apparatus including a pair of arcuate arms connected to a common support member at spaced pivot joints. A shaft is connected to each arm and to a lever arm wherein movement of the lever arm by an actuator causes the shaft to rotate to move the gripping arms. Smith et al describe a grasping device including a single actuator pivotally connected to an arcuate arm and a connecting rod attached to this arm to operate a second arcuate arm to grasp an object of interest. Pickrell describes a gripping device having a single actuator attached to a lever which, in turn, is attached to rotate an arcuate arm having gears meshed with gears operating a second arcuate arm. The arms carry a belt or flexible mechanism to enclose and grab circular objects of various sizes. In each of these systems a relatively complex linkage mechanism is required to move the arms.
Grasping devices including multiple actuators and two single member arcuate arms have been described in U.S. Reissue Pat. No. 34,292, and U.S. Pat. Nos. 4,227,849 and 4,872,801. In each these patents, the arms are pivotally attached to a common support member and operated by hydraulic cylinders pivotally attached to the same support member.
A grasping device including multiple actuators and arms having multiple members is described in U.S. Pat. No. 4,669,940, issued to Englehardt et al. In this patent, a pair of straight secondary arms are pivoted to a common support member inside a pair of angled primary arms. The secondary arms roll along the inside of the primary arms to form a hexagon as the primary arms are pushed together by hydraulic cylinders.
U.S. Pat. No. 5,092,731, issued to Jones et al, describes a grasping device including two compound (segmented) arcuate arms linked to an I-beam member operated by actuators. The inner portion or segment member of each arm is slidably attached to the I-beam member which, in turn, is pivotally attached to the common support member. The I-beams rotate to move the inner members between an open and a closed position as the actuating hydraulic cylinders retract and expand, respectively. The outer portions or segment members of each arm are pivotally attached to the inner member and rollers at the end of each I-beam cause the outer members to rotate about the pivot joint to grasp an object.
The devices discussed above are designed to grasp circular objects. A device for lifting and holding containers having a plurality of basic shapes is described in U.S. Pat. No. 4,401,407, to Breckenridge. Breckenridge describes a device having a pair of arms including an inner member pivoted at one end to a frame and an outer member pivoted between its ends to the second end of the inner member. A complex linkage mechanism is attached between the frame and the two members for coordinating movement of the inner and outer members. While the mechanism is functional, a mechanically simpler device for grasping containers having a plurality of shapes is desired.
PCT International Application Publication No. WO 92/01612 describes a device for grasping containers of several shapes. The described device includes oppositely disposed compound articulated arms pivotally attached to a central support member. Each arm includes an inner and an outer member curved to fit around a container and having grip padding for holding the container. In operation, the arms are moved by four actuators. However, the shape of the arms and the grip padding is a compromise, not shaped to fit snugly around the corners of a rectangular object. The corners of a rectangular object fall between the grip padding or are contacted at an angle which limits the ability of the device to manipulate rectangular objects.
It is accordingly a principal object of the invention to provide a mechanically simplified device for handling objects of various shapes.
Another object of the invention is to provide a grasping device for securely grasping objects of various shapes.
Yet another object of the invention is to provide a mechanically simplified grasping device including actuators for grasping objects of various shapes.
Still another object of the invention is to provide a mechanically simplified grasping device including two single element arms wherein each arm is connected to an actuator for grasping objects of various shapes.
A further object of the invention is to provide a simplified grasping device including two compound arms each having an inner member and an outer member wherein only each outer member is connected to an actuator for grasping objects of various shapes.
A still further object of the invention is to provide a simplified grasping device including four actuators for securely grasping objects of various shapes.
A yet still further object of the invention is to provide a simplified grasping device including two arms each having an inner member and an outer member and four actuators connected to the arms for securely grasping objects of various shapes.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art through familiarity with the summary of the invention, detailed description, claims, and drawings herein.